Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Datasheet

Pacifastacus leniusculus
(American signal crayfish)

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Datasheet

Pacifastacus leniusculus (American signal crayfish)

Summary

  • Last modified
  • 08 November 2018
  • Datasheet Type(s)
  • Invasive Species
  • Natural Enemy
  • Host Animal
  • Preferred Scientific Name
  • Pacifastacus leniusculus
  • Preferred Common Name
  • American signal crayfish
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Metazoa
  •     Phylum: Arthropoda
  •       Subphylum: Crustacea
  •         Class: Malacostraca
  • Summary of Invasiveness
  • Native to western North America, Pacifastacus leniusculus, the American signal crayfish, is one of the top three most invasive crayfish species in the world and the most widespread non-native crayfish...

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Pictures

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PictureTitleCaptionCopyright
Pacifastacus leniusculus (American signal crayfish); adult, in habitat.
TitleAdult
CaptionPacifastacus leniusculus (American signal crayfish); adult, in habitat.
Copyright©Trevor Renals - CC BY 2.0
Pacifastacus leniusculus (American signal crayfish); adult, in habitat.
AdultPacifastacus leniusculus (American signal crayfish); adult, in habitat.©Trevor Renals - CC BY 2.0
Pacifastacus leniusculus (American signal crayfish); adult male.
TitleAdult
CaptionPacifastacus leniusculus (American signal crayfish); adult male.
Copyright©Crown Copyright 2009 - Please acknowledge GBNNSS
Pacifastacus leniusculus (American signal crayfish); adult male.
AdultPacifastacus leniusculus (American signal crayfish); adult male.©Crown Copyright 2009 - Please acknowledge GBNNSS
Pacifastacus leniusculus (American signal crayfish); ventral view of adult female - note egg mass.
TitleAdult
CaptionPacifastacus leniusculus (American signal crayfish); ventral view of adult female - note egg mass.
Copyright©Crown Copyright 2009 - Please acknowledge Matt Brazier - Environment Agency
Pacifastacus leniusculus (American signal crayfish); ventral view of adult female - note egg mass.
AdultPacifastacus leniusculus (American signal crayfish); ventral view of adult female - note egg mass.©Crown Copyright 2009 - Please acknowledge Matt Brazier - Environment Agency
Pacifastacus leniusculus (American signal crayfish); adult, dorsal view.
TitleAdult
CaptionPacifastacus leniusculus (American signal crayfish); adult, dorsal view.
Copyright©Crown Copyright 2009 - Please acknowledge GBNNSS
Pacifastacus leniusculus (American signal crayfish); adult, dorsal view.
AdultPacifastacus leniusculus (American signal crayfish); adult, dorsal view.©Crown Copyright 2009 - Please acknowledge GBNNSS
Pacifastacus leniusculus (American signal crayfish); adult. Ventral view, note prominent red claws.
TitleAdult
CaptionPacifastacus leniusculus (American signal crayfish); adult. Ventral view, note prominent red claws.
Copyright©Crown Copyright 2009 - Please acknowledge GBNNSS
Pacifastacus leniusculus (American signal crayfish); adult. Ventral view, note prominent red claws.
AdultPacifastacus leniusculus (American signal crayfish); adult. Ventral view, note prominent red claws.©Crown Copyright 2009 - Please acknowledge GBNNSS
Pacifastacus leniusculus (American signal crayfish); adult, ventral view. Note prominent red claws and size, compared with human hand.
TitleAdult
CaptionPacifastacus leniusculus (American signal crayfish); adult, ventral view. Note prominent red claws and size, compared with human hand.
Copyright©Trevor Renals - CC BY 2.0
Pacifastacus leniusculus (American signal crayfish); adult, ventral view. Note prominent red claws and size, compared with human hand.
AdultPacifastacus leniusculus (American signal crayfish); adult, ventral view. Note prominent red claws and size, compared with human hand.©Trevor Renals - CC BY 2.0
Pacifastacus leniusculus (American signal crayfish); adult, anterior view.
TitleAdult
CaptionPacifastacus leniusculus (American signal crayfish); adult, anterior view.
Copyright©Crown Copyright 2009 - Please acknowledge GBNNSS
Pacifastacus leniusculus (American signal crayfish); adult, anterior view.
AdultPacifastacus leniusculus (American signal crayfish); adult, anterior view.©Crown Copyright 2009 - Please acknowledge GBNNSS

Identity

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Preferred Scientific Name

  • Pacifastacus leniusculus Dana, 1852

Preferred Common Name

  • American signal crayfish

International Common Names

  • English: crawfish; North American signal crayfish; signal crayfish; signal crayfish, American

Local Common Names

  • Czech Republic: rak signální
  • Denmark: signalkrebs
  • Estonia: signaalvähk
  • Finland: täplärapu
  • Germany: Signalkrebs
  • Latvia: signalvezis
  • Lithuania: žymetasis vežys
  • Netherlands: Californische rivierkreeft
  • Norway: signalkreps
  • Poland: rak sygnalowy

Summary of Invasiveness

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Native to western North America, Pacifastacus leniusculus, the American signal crayfish, is one of the top three most invasive crayfish species in the world and the most widespread non-native crayfish in Europe. It has been found in 28 territories in Europe since the 1960s, largely due to its high adaptability to a wide range of environments. P. leniusculus is now widely cultivated in Europe and has provided a culinary substitute following the decline of the native European species, Astacus astacus, from crayfish plague. In fact, its use for restocking crayfish plague-devastated European waters is the primary reason for its current wide distribution in Europe. Ironically, P. leniusculus, though resistant to crayfish plague, is a vector of the causal factor, and has been implicated in many plague outbreaks, which have seriously impacted native crayfish populations.  

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Metazoa
  •         Phylum: Arthropoda
  •             Subphylum: Crustacea
  •                 Class: Malacostraca
  •                     Subclass: Eumalacostraca
  •                         Order: Decapoda
  •                             Suborder: Reptantia
  •                                 Unknown: Astacoidea
  •                                     Family: Cambaridae
  •                                         Genus: Pacifastacus
  •                                             Species: Pacifastacus leniusculus

Description

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P. leniusculus has a smooth, reddish-brown exoskeleton and bright red undersides to the chelae. It has a white dorsal patch at the junction of the moveable and fixed finger of the chela (Lewis, 2002). Male crayfish can reach a length of 16 cm, while females can only achieve a maximum size of 12 cm. Age at maturity varies from 1 to 3 years, and a life expectancy of up to 20 years is possible.

Distribution

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P. leniusculus is distributed from British Columbia in Canada at the northern part of its range, south to central California and east to Utah and Montana in the USA. In the 1960s, P. leniusculus was introduced into Europe and now occurs in many countries from the UK and France in the west, to Russia in the east. A population near Inverness, Scotland constitutes the limit of the species range in the northwest; the northern extent is Norway, Sweden and Finland, while the southern extent is the Iberian Peninsula. There are also satellite populations in Greece and Cyprus. P. leniusculus has also been introduced outside of Europe, to Japan (Hiruta, 1996).

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes

Asia

JapanPresentIntroducedHiruta, 1996
-HokkaidoPresentIntroducedHiruta, 1996

North America

CanadaPresentNativeLarson and Olden, 2011
USAPresentPresent based on regional distribution.
-AlaskaPresentUnited States Geological Survey, 2011
-CaliforniaPresentNative Invasive Lewis, 2002; United States Geological Survey, 2011
-IdahoPresentNativeLewis, 2002
-MontanaPresentNativeLarson and Olden, 2011
-NevadaPresentNativeLewis, 2002; United States Geological Survey, 2011
-OregonPresentNativeLarson and Olden, 2011
-UtahPresentNativeLarson and Olden, 2011
-WashingtonPresentNativeLarson and Olden, 2011

Europe

AustriaPresentIntroducedKouba et al., 2014
BelgiumPresentIntroducedKouba et al., 2014
CroatiaPresentIntroducedKouba et al., 2014
CyprusPresentIntroducedKouba et al., 2014
Czech RepublicPresentIntroducedKouba et al., 2014
DenmarkPresentIntroducedSkov et al., 2011
EstoniaPresentIntroducedKouba et al., 2014Established
FinlandPresentIntroducedKouba et al., 2014
FrancePresentIntroducedKouba et al., 2014
GermanyPresentIntroducedKouba et al., 2014
GreecePresentIntroducedKouba et al., 2014
HungaryPresentIntroducedKouba et al., 2014
ItalyPresentIntroducedKouba et al., 2014
LatviaPresentIntroducedJohnsen and Taugbøl, 2010Rare
LithuaniaPresentIntroducedKouba et al., 2014Common
LuxembourgPresentIntroducedKouba et al., 2014
NetherlandsPresentIntroducedKouba et al., 2014
NorwayPresentIntroducedKouba et al., 2014
PolandPresentIntroducedKouba et al., 2014
PortugalPresentIntroducedBernardo et al., 2011
RomaniaPresentIntroducedPârvulescu et al., 2012
Russian FederationPresentIntroducedKouba et al., 2014
SlovakiaPresentIntroducedKouba et al., 2014
SloveniaPresentIntroducedKouba et al., 2014
SpainPresentIntroducedKouba et al., 2014
SwedenPresentIntroducedKouba et al., 2014
SwitzerlandPresentIntroducedKouba et al., 2014
UKPresentIntroducedKouba et al., 2014

History of Introduction and Spread

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See Johnsen and Taugbøl (2010).

Introductions

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Introduced toIntroduced fromYearReasonIntroduced byEstablished in wild throughReferencesNotes
Natural reproductionContinuous restocking
Japan Aquaculture (pathway cause)Unknown No No Hiruta (1996)
Sweden California 1959 Aquaculture (pathway cause)Private sector Yes No Fürst (1977)
UK Sweden 1976 Aquaculture (pathway cause)Unknown Yes No Hogger (1986)

Habitat

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P. leniusculus can be found in a variety of habitats, from small streams to large rivers and natural lakes. It is also known to occur in brackish waters along the Pacific Coast in salinities as high as 20 ppt (Riegel, 1959). Its ability to tolerate water temperatures up to 33°C has allowed it to prosper in many environments.

Habitat List

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CategorySub-CategoryHabitatPresenceStatus

Natural Food Sources

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Food SourceLife StageContribution to Total Food Intake (%)Details
Aquatic insects (Ephemeroptera, Chironomidae, Coleoptera, Plecoptera, Trichoptera and Diptera) Adult/Fry
Detritus Adult/Fry
Plant material (alder, maple leaves) Adult

Climate

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ClimateStatusDescriptionRemark
C - Temperate/Mesothermal climate Preferred Average temp. of coldest month > 0°C and < 18°C, mean warmest month > 10°C

Water Tolerances

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ParameterMinimum ValueMaximum ValueTypical ValueStatusLife StageNotes
Bicarbonate (mg/l) 12 14 Optimum Egg
Water temperature (ºC temperature) 15 23 Optimum Adult

Natural enemies

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Natural enemyTypeLife stagesSpecificityReferencesBiological control inBiological control on
Alcedo atthis Predator Adult Hogger, 1988
Anguilla anguilla Predator Adults Blake and Hart, 1995
Ardea cinerea Predator Adult Hogger, 1988
Lutra lutra Predator Adult Hogger, 1988
Micropterus dolomieu Predator Adult Pflug and Pauley, 1984
Neovison vison Predator Adult Hogger, 1988
Perca fluviatilis Predator Adult Appelberg and Odelstrom, 1987; Soderback, 1994
Procyon lotor Predator Adult Hogger, 1988
Prosopium williamsoni Predator Adult Lewis, 1999
Ptychocheilus oregonensis Predator Adult Jeppson and Platts, 1958
Salmo trutta Predator Adult Lewis, 1999
Silurus glanis Predator not specific

Pathway Causes

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CauseNotesLong DistanceLocalReferences
Intentional releaseIllegal Yes Johnsen and Taugbøl, 2010
Stocking Yes Johnsen and Taugbøl, 2010

Pathway Vectors

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VectorNotesLong DistanceLocalReferences
WaterNatural migration Yes Johnsen and Taugbøl, 2010

Impact Summary

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CategoryImpact
Fisheries / aquaculture Positive
Native fauna Negative
Rare/protected species Negative

Environmental Impact

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The introduction of P. leniusculus has had negative impacts on native crayfish populations globally. Native crayfish species are frequently replaced due to having lower fecundities (Eng and Daniels, 1982), an inferior ability to compete for shelter leading to an increased susceptibility to predation (Dunn et al., 2009), vulnerability to reproductive interference leading to diminished recruitment (Westman et al., 2002) or due to being directly predated upon (Nataka and Goshima, 2006). The spread of P. leniusculus throughout Europe has enabled Aphanomyces astaci, the crayfish plague, to spread as well, decimating native crayfish populations (Holdich et al., 2009).

P. leniusculus presence in the River Clyde, Scotland, was associated with a 40% reduction in benthic invertebrate density compared to P. leniusculus absence, with an associated reduction in species diversity (Crawford et al., 2006). This impact on macroinvertebrate communities was alleviated by intensive removal of signal crayfish using traps (Moorhouse et al., 2014). In two similar rivers in Yorkshire (UK), high P. leniusculus densities correlated with low salmonid fish densities (brown trout, Salmo trutta), whilst high native white-clawed crayfish, Austropotamobius pallipes, densities correlated with high fish densities, suggesting a population level impact of P. leniusculus on fish communities (Peay et al., 2009). Melero et al. (2014) have also demonstrated an increased density and resilience to control of invasive non-native mammalian carnivore populations such as the American mink, Neovison vison, in ecosystems with established invasive non-native crayfish populations, due the availability of a superabundant prey item.

The burrows of signal crayfish lead to bank erosion and increased fluvial sediment mobilisation, which could eventually contribute to bank collapse (Harvey et al., 2011).

For further impacts see Johnsen and Taugbøl (2010).

Threatened Species

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Threatened SpeciesConservation StatusWhere ThreatenedMechanismReferencesNotes
Austropotamobius pallipes (freshwater white-clawed crayfish)EN (IUCN red list: Endangered) EN (IUCN red list: Endangered)
Pacifastacus fortis (Shasta crayfish)CR (IUCN red list: Critically endangered) CR (IUCN red list: Critically endangered); USA ESA listing as endangered species USA ESA listing as endangered speciesCaliforniaCompetition - monopolizing resources; PredationUS Fish and Wildlife Service, 2009

Risk and Impact Factors

Top of page Invasiveness
  • Proved invasive outside its native range
  • Has a broad native range
  • Abundant in its native range
  • Highly adaptable to different environments
  • Is a habitat generalist
  • Capable of securing and ingesting a wide range of food
  • Highly mobile locally
Impact outcomes
  • Modification of natural benthic communities
  • Reduced native biodiversity
  • Threat to/ loss of native species
Impact mechanisms
  • Competition - monopolizing resources
  • Competition
  • Pest and disease transmission
  • Predation
Likelihood of entry/control
  • Highly likely to be transported internationally deliberately
  • Difficult/costly to control

Uses List

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Animal feed, fodder, forage

  • Bait/attractant

Human food and beverage

  • Fresh meat
  • Live product for human consumption
  • Whole

Similarities to Other Species/Conditions

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P. leniusculus is similar in appearance to the noble crayfish, Astacus astacus. The main difference is the presence in P. leniusculus of the white dorsal patch at the junction of the moveable and fixed finger of the chela (Lewis, 2002). P. leniusculus also lacks the spine on each side of the carapace which is present in A. astacus. For more information see section on species identification in Johnsen and Taugbøl (2010).

Prevention and Control

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For information on this, see Stebbing et al. (2014).

References

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Ackefors H, Lindqvist OV, 1994. Cultivation of freshwater crayfishes in Europe. In: Huner JV, ed. Freshwater Crayfish Aquaculture. New York, USA: Haworth Press, 157-216

Alderman DJ, Polglase JL, 1988. Pathogens, parasites and commensals. Freshwater crayfish. Biology, management and exploitation., 167-212

Appelberg M, Odelstrom T, 1987. Interaction between European perch (Perca fluviatilis) and juvenile Pacifastacus leniusculus (Dana) in a pond experiemnt. Freshwater Crayfish, 7:37-45

Bernardo, J. M., Costa, A. M., Bruxelas, S., Teixeira, A., 2011. Dispersal and coexistence of two non-native crayfish species (Pacifastacus leniusculus and Procambarus clarkii) in NE Portugal over a 10-year period. Knowledge and Management of Aquatic Ecosystems, 401(28), 1-13. doi: 10.1051/kmae/2011047

Blake MA, Hart PJB, 1995. The vulnerability of juvenile signal crayfish to perch and eel predation. Freshwater Biology, 33, 233-244.

Crawford, L., Yeomans, W. E., Adams, C. E., 2006. The impact of introduced signal crayfish Pacifastacus leniusculus on stream invertebrate communities. Aquatic Conservation: Marine and Freshwater Ecosystems, 16(6), 611-621. http://www3.interscience.wiley.com/cgi-bin/abstract/112597211/ABSTRACT doi: 10.1002/aqc.761

Dunn, J. C., McClymont, H. E., Christmas, M., Dunn, A. M., 2009. Competition and parasitism in the native white clawed crayfish Austropotamobius pallipes and the invasive signal crayfish Pacifastacus leniusculus in the UK. Biological Invasions, 11(2), 315. http://www.springerlink.com/content/9095w4r00p035l7j/?p=0c1a2f95bea14a67a6d603f344c29c3b&pi=14 doi: 10.1007/s10530-008-9249-7

Eng LL, Daniels RA, 1982. Life history, distribution and status of Pacifastacus fortis (Decapoda: Astacidae). California Fish and Game, 68(4):197-212

Fürst M, 1977. Introduction of Pacifastacus leniusculus (Dana) into Sweden: methods, results and management. Freshwater Crayfish, 3, 229-247.

Gonzalez J, Carral JM, Celada JD, Sáez-Royuela M, Gaudioso VR, Fernández R, López-Baissón C, 1993. Management of crayfish eggs (Pacifastacus leniusculus) for intensification of juvenile production. Freshwater Crayfish, 9:144-146

Gydemo R, 1996. Signal crayfish, Pacifastacus leniusculus, as a vector for Psorospermium haeckeli to noble crayfish, Astacus astacus. Aquaculture, 148(1):1-9

Harvey, G. L., Moorhouse, T. P., Clifford, N. J., Henshaw, A. J., Johnson, M. F., Macdonald, D. W., Reid, I., Rice, S. P., 2011. Evaluating the role of invasive aquatic species as drivers of fine sediment-related river management problems: the case of the signal crayfish (Pacifastacus leniusculus). Progress in Physical Geography, 35(4), 517-533. http://ppg.sagepub.com/ doi: 10.1177/0309133311409092

Hiruta S, 1996. The presence of signal crayfish in Hokkaido, Japan. Crayfish News, 19:1

Hogger JB, 1986. Aspects of the introduction of “signal crayfish”, Pacifastacus leniusculus (Dana), into the Southern United Kingdom. 1. Growth and survival. Aquaculture, 58(1-2), 27-44.

Hogger JB, 1988. Ecology, population biology, and behaviour. In: Holdich DM, Lowery RS, eds. Freshwater Crayfish. Biology, Management and Exploitation. London, Portland: Croom Helm Ltd., 114-144, 424-479

Holdich, D. M., Reynolds, J. D., Souty-Grosset, C., Sibley, P. J., 2009. A review of the ever increasing threat to European crayfish from non-indigenous crayfish species. Knowledge and Management of Aquatic Ecosystems, (No.394/395), 11. http://www.kmae-journal.org/articles/kmae/pdf/2009/03/kmae09055.pdf doi: 10.1051/kmae/2009025

Jeppson PW, Platts WS, 1958. Ecology andcontrol of the Columbia squawfish in Northern Idaho lakes. Transactions of the American Fisheries Society, 88:197-202

Johnsen SI, Taugbøl T, 2010. Pacifastacus leniusculus. NOBANIS Invasive Alien Species Fact Sheet. Online Database of the North European and Baltic Network on Invasive Alien Species - NOBANIS. http://www.nobanis.org

Jussila J, Hytinen L, Lahti E, Pulkkinen V, 1990. Mikkelin laaninraputalouden elvytyssuunnitelma vuosille 1990-95. Mikkelin kalastuspiirin julkaisu nro 4

Jussila J, Mannonen A, 1995. Crayfish culture in Finland, Northern Europe. Marron Grower’s Bulletin, 17(1):2-6

Kouba A, Petrusek A, Kozák P, 2014. Continental-wide distribution of crayfish species in Europe: update and maps. Knowledge and Management of Aquatic Ecosystems, 413(5), 1-31.

Larson ER, Olden JD, 2011. The state of crayfish in the Pacific Northwest. Fisheries, 36(2), 60-73.

Lewis SD, 1999. Abundance, activity and diet of littoral fish in Lake Billy Chinook, Lake Simtustus and Reregulating Reservoir, Oregon, 1997-1999. Portland General Electric Company, Portland, Oregon, USA

Lewis SD, 2002. Pacifastacus. Biology of freshwater crayfish, 511-540

Melero, Y., Palazón, S., Lambin, X., 2014. Invasive crayfish reduce food limitation of alien American mink and increase their resilience to control. Oecologia, 174(2), 427-434. http://link.springer.com/article/10.1007%2Fs00442-013-2774-9 doi: 10.1007/s00442-013-2774-9

Moorhouse, T. P., Poole, A. E., Evans, L. C., Bradley, D. C., Macdonald, D. W., 2014. Intensive removal of signal crayfish (Pacifastacus leniusculus) from rivers increases numbers and taxon richness of macroinvertebrate species. Ecology and Evolution, 4(4), 494-504. http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)2045-7758 doi: 10.1002/ece3.903

Nakata K, Goshima S, 2006. Asymmetry in mutual predation between the endangered Japanese native crayfish Cambariodes japonicus and the North American invasive crayfish Pacifastacus leniusculus: a possible reason for species replacement. Journal of Crustacean Biology, 26(2), 134-140.

Nylund V, Westman K, 1981. Frequency of visible symptoms of the crayfish plague fungus (Aphanomyces astaci) on the American crayfish (Pacifastacus leniusculus) in natural populations in Finland. Freshwater Crayfish, 5:277-283

Pârvulescu, L., Schrimpf, A., Kozubíková, E., Resino, S. C., Vr?lstad, T., Petrusek, A., Schulz, R., 2012. Invasive crayfish and crayfish plague on the move: first detection of the plague agent Aphanomyces astaci in the Romanian Danube. Diseases of Aquatic Organisms, 98(1), 85-94. http://www.int-res.com/abstracts/dao/v98/n1/p85-94/ doi: 10.3354/dao02432

Peay, S., Guthrie, N., Spees, J., Nilsson, E., Bradley, P., 2009. The impact of signal crayfish (Pacifastacus leniusculus) on the recruitment of salmonid fish in a headwater stream in Yorkshire, England. Knowledge and Management of Aquatic Ecosystems, (No.394/395), 12. http://www.kmae-journal.org/articles/kmae/pdf/2009/03/kmae09022.pdf doi: 10.1051/kmae/2010003

Pflug DE, Pauley GB, 1984. Biology of smallmouth bass (Micropterus dolomieui) in Lake Sammanish, Washington. Northwest Science, 58(2):118-130

Riegel JA, 1959. The systematics and distribution of crayfish in California. California Fish and Game, 45:29-50

Skov, C., Aarestrup, K., Sivebæk, F., Pedersen, S., Vr?lstad, T., Berg, S., 2011. Non-indigenous signal crayfish Pacifastacus leniusculus are now common in Danish streams: preliminary status for national distribution and protective actions. Biological Invasions, 13(6), 1269-1274. http://www.springerlink.com/content/m751771l68345507/ doi: 10.1007/s10530-010-9901-x

Soderback B, 1994. Interactions among juveniles of two freshwater crayfish species and a predatory fish. Oecologia, 100:229-235

Stebbing, P., Longshaw, M., Scott, A., 2014. Review of methods for the management of non-indigenous crayfish, with particular reference to Great Britain. Ethology Ecology & Evolution, 26(2/3), 204-231. http://www.tandfonline.com/loi/teee20

United States Geological Survey, 2011. Pacifastacus leniusculus. USGS Nonindigenous Aquatic Species Database. Gainesville, Florida, USA: USGS. http://nas.usgs.gov/queries/factsheet.aspx?SpeciesID=200

US Fish and Wildlife Service, 2009. Shasta crayfish, Pacifastacus fortis, 5-year review: Summary and evalution. In: Shasta crayfish, Pacifastacus fortis, 5-year review: summary and evalution : US Fish and Wildlife Service.22 pp.

Westman K, Pursiainen M, Westman P, eds, 1990. The situation of crayfish stocks, fisheries, diseases and crayfish culture in Europe - a review. In: Status of Crayfish Stocks, Fisheries, Diseases and Culture in Europe, pp. 5-31. Report of the FAO European Inland Fisheries Advisory Commission (EIFAC) Working Party of Crayfish, Helsinki, FInland

Westman, K., Savolainen, R., Julkunen, M., 2002. Replacement of the native crayfish Astacus astacus by the introduced species Pacifastacus leniusculus in a small, enclosed Finnish lake: a 30-year study. Ecography, 25(1), 53-73. doi: 10.1034/j.1600-0587.2002.250107.x

Wolf YS, 2004. Growth and macronutrient requirements of signal crayfish Pacifastacus leniusculus (Dana). PhD thesis. Germany: Christian Albrecht Universitat Kiel. Online at http://e-diss.uni-kiel.de/diss_1154/d1154.pdf. Accessed 23 September 2004

Contributors

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27/06/14 Updated by:

Rupert Houghton, School of Biological Sciences, University of Aberdeen, UK

27/09/04 Original text by:
Uma Sabapathy Allen, Human Sciences, CAB International, Wallingford, Oxon, OX10 8DE, UK

Distribution Maps

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